Historically, the task of mapping the ocean floor has lagged behind efforts to chart the surfaces ... have the potential to ...

This story appears in the September 2012 issue of National Geographic magazine ... Mars may exist than of the remotest parts of the ocean floor. Scientists don’t often explore their slopes ...

Since National Geographic began making maps in 1915 ... ocean waters to the north Extending from the surface to the ocean floor, the ACC transports more water than any other ocean current.